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<span id="S_002f390-Function-Attributes"></span><div class="header">
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<hr>
<span id="S_002f390-Function-Attributes-1"></span><h4 class="subsection">6.33.28 S/390 Function Attributes</h4>

<p>These function attributes are supported on the S/390:
</p>
<dl compact="compact">
<dd><span id="index-hotpatch-function-attribute_002c-S_002f390"></span>
</dd>
<dt><code>hotpatch (<var>halfwords-before-function-label</var>,<var>halfwords-after-function-label</var>)</code></dt>
<dd>
<p>On S/390 System z targets, you can use this function attribute to
make GCC generate a &ldquo;hot-patching&rdquo; function prologue.  If the
<samp>-mhotpatch=</samp> command-line option is used at the same time,
the <code>hotpatch</code> attribute takes precedence.  The first of the
two arguments specifies the number of halfwords to be added before
the function label.  A second argument can be used to specify the
number of halfwords to be added after the function label.  For
both arguments the maximum allowed value is 1000000.
</p>
<p>If both arguments are zero, hotpatching is disabled.
</p>
<span id="index-target-function-attribute-4"></span>
</dd>
<dt><code>target (<var>options</var>)</code></dt>
<dd><p>As discussed in <a href="Common-Function-Attributes.html">Common Function Attributes</a>, this attribute
allows specification of target-specific compilation options.
</p>
<p>On S/390, the following options are supported:
</p>
<dl compact="compact">
<dt>&lsquo;<samp>arch=</samp>&rsquo;</dt>
<dt>&lsquo;<samp>tune=</samp>&rsquo;</dt>
<dt>&lsquo;<samp>stack-guard=</samp>&rsquo;</dt>
<dt>&lsquo;<samp>stack-size=</samp>&rsquo;</dt>
<dt>&lsquo;<samp>branch-cost=</samp>&rsquo;</dt>
<dt>&lsquo;<samp>warn-framesize=</samp>&rsquo;</dt>
<dt>&lsquo;<samp>backchain</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-backchain</samp>&rsquo;</dt>
<dt>&lsquo;<samp>hard-dfp</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-hard-dfp</samp>&rsquo;</dt>
<dt>&lsquo;<samp>hard-float</samp>&rsquo;</dt>
<dt>&lsquo;<samp>soft-float</samp>&rsquo;</dt>
<dt>&lsquo;<samp>htm</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-htm</samp>&rsquo;</dt>
<dt>&lsquo;<samp>vx</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-vx</samp>&rsquo;</dt>
<dt>&lsquo;<samp>packed-stack</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-packed-stack</samp>&rsquo;</dt>
<dt>&lsquo;<samp>small-exec</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-small-exec</samp>&rsquo;</dt>
<dt>&lsquo;<samp>mvcle</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-mvcle</samp>&rsquo;</dt>
<dt>&lsquo;<samp>warn-dynamicstack</samp>&rsquo;</dt>
<dt>&lsquo;<samp>no-warn-dynamicstack</samp>&rsquo;</dt>
</dl>

<p>The options work exactly like the S/390 specific command line
options (without the prefix <samp>-m</samp>) except that they do not
change any feature macros.  For example,
</p>
<div class="example">
<pre class="example"><code>target(&quot;no-vx&quot;)</code>
</pre></div>

<p>does not undefine the <code>__VEC__</code> macro.
</p></dd>
</dl>




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